After the first (main) earthquake, other smaller shocks may occur at times for: about a day
several hours
several weeks
almost a year

It's basically a smaller earthquake that happens after the main quake, in the same area. If it's stronger than the first quake, it's renamed as the main earthquake and the original main quake becomes known as a foreshock. Aftershocks can happen for up to two years after the original earthquake, losing power over time. So i'd say it's either between, Several weeks and a year.

what does the table look like